In 1517, Martin Luther wrote to the Archbishop of Mainz about the selling of pardons. 'Spare me ... that I, the dregs of humanity, have so much boldness that I have dared to think of a letter to the height of your Sublimity.' He went on to suggest that it was wrong that people should be allowed to believe 'that so soon as they cast their contributions into the money box, souls fly out of purgatory'.

The selling of indulgences died out in the Reformation, but the instinct to buy relief from penalty and guilt did not. In fact, it has experienced a resurgence in the practice of carbon-offsetting, the system whereby individuals or companies compensate for their carbon emissions by donating money to reforestation, renewables and energy-saving schemes. Sins of emission are therefore expunged or, as we like to say, made carbon-neutral.

In themselves, there's nothing wrong with these schemes, but let me tell you that I have some minor experience of reforestation and the idea that you can buy a return ticket to Miami now and assuage your guilt by giving money for planting trees is as silly as buying a pardon for gluttony.

Each year, I grow about 40 trees from seed, mostly oak, chestnut, sweet chestnut, beech and ash but also rarer species from seeds I pick up abroad and in London parks. It will take another 50 to 75 years for my trees to have any impact on the climate. A million oaks planted now will do nothing for the carbon emissions generated by me or Mr Blair and his family.

Nor will buying energy-efficient light bulbs for the developing world or investing in renewables research. What needs to happen is that each one of us tries to reduce our personal CO2 emission and the first step is to ditch the unreason that says you may continue to do something but at the same time somehow not be doing it because you are bunging a few quid towards the purchase of an energy-efficient stove in Tanzania.

The same unreason sees people jetting to the Alps, then wondering why there's no snow; it produced no less than three Daily Telegraph commentators last week to say they would continue to fly as often as they liked regardless of the impact; and it allowed the Prime Minister to claim that the answer lies in making planes more energy-efficient rather than requiring anyone to make sacrifices when it comes to their holidays.

No one conceives the grand strategy that balances the interests of the economy, convenience and personal freedom with the environment and at the same time averts the national gridlock of the future that we sometimes glimpse on the M25 and M1.

What we get are drift and fluctuations in policy with central government more often than not simply eyeing up taxation opportunities. Nowhere is the all-round uselessness of New Labour's strategies better seen than on the rail network which should be one of the answers to our problems over the next 30 years. Yet instead of encouraging people to leave the road to use the improved railways services, rail fares are being manipulated by the government to deter them. At the beginning of the year, fares went up between 4.3 and 7.3 per cent, a little less than three times the inflation rate.

Added to this, cuts in government subsidy to the rail companies mean they have reduced their services. First Great Western, serving the West Country and the Thames Valley, has removed 700 services over the last month and added to passenger discomfort by leasing fewer carriages. It turns out this was part of the company's new contract with the Department of Transport, which has also demanded a premium of more than £1bn. Money is being taken out rather than invested.

The signs are that people want to take the train - passenger numbers are up - but if they happen to live in an area served by First Great Western, they naturally give up and resort to the car, so adding to congestion and the amount of CO2 the nation produces.

In some distant wing of the Department of Transport, there is a group of civil servants who are presumably unaware of these manoeuvres for they are working on the road pricing scheme, which is designed to do the opposite - that is, ease road congestion by encouraging people to leave their cars at home and take the train or the low-cost but heavily polluting option of a domestic flight.

The technology being considered by the government would place a tracking device in every vehicle, which would cost about £200 and allow a charge to be levied according the number of miles the vehicle is driven over a period of a month. Quite apart from the enormous revenue generated, there will be the side benefit for the government of acquiring a minute record of every one's journeys, which for New Labour must be an alluring plus.

Once we have such a system, there will be no guarantee that the money will be used to improve public transport, no guarantee against the high-handed exploitation of drivers that you see in London, where the congestion charge zone is about to be extended against the majority's wishes and where the daily charge was raised to £8, despite Ken Livingstone's assurances that it wouldn't be. I happen to think the charge is a good idea on environmental grounds, though the gains are not enormous. But there is no escaping the fact that this is primarily taxation and that Livingstone is milking the system.

But the main point, which holds me fascinated like some devilish optical illusion, is that the Department of Transport is set on parallel courses which simultaneously encourage and discourage the use of energy-efficient transport while tacitly providing an incentive to use the greatest polluters of them all - the plane.

Because we have at the head of the Department of Transport a bright young Scot named Douglas Alexander, whose only experience of running something outside government was gained in a solicitor's office, and because we have a Prime Minister who pays lip service to reducing emissions but clearly does not feel it in his heart, there seems little hope that this era of unreason and drift will end any time soon. It will take more than few indulgences to stop climate change.